Panasonic CS-DZ50VKE Service Manual page 91

15.1.4 Compressor Overheating Prevention Control

Instructed frequency for compressor operation will be regulated by compressor discharge temperature. The
changes of frequency are as below.

If compressor discharge temperature exceeds 103°C, compressor will be stopped, occurs 4 times per 20 minutes,
timer LED will be blinking. ("F97" is indicated.)
15.1.5 Low Pressure Prevention Control (Gas Leakage Detection)

Control start conditions
For 5 minutes, the compressor continuously operates and outdoor total current is between 1.22A and 1.38 A
o
(DZ/PZ/UZ25/35VK), between 0.75A and 0.95A (DZ/PZ/UZ50VK).
During Cooling and Soft Dry operations:
o
Indoor suction temperature - indoor piping temperature is below 4°C.
During Heating operations :
o
Indoor piping temperature - indoor suction is under 5°C.

Control contents
Compressor stops (and restart after 3 minutes).
o
If the conditions above happen 2 times within 20 minutes, the unit will:
o
 Stop operation
 Timer LED blinks and "F91" indicated.
15.1.6 Low Frequency Protection Control 1

When the compressor operate at frequency lower than 24 Hz continued for 20 minutes, the operation frequency
will be changed to 23 Hz for 2 minutes.
15.1.7 Low Frequency Protection Control 2

When all the below conditions comply, the compressor frequency will change to lower frequency.
Indoor intake air (°C)
Outdoor air (°C)
Indoor heat exchanger (°C)
Fre quency
103°C
99°C
96°C
Comp temp
Temperature, T, for:
Compressor =
OFF
Compressor Frequency
Reduce
Compressor Frequency
Limited
Free
Cooling/Soft Dry
T < 14 or T ≥ 30
T < 13 or T ≥ 38
T < 30
91
88°C
87°C
86°C
Heating
T < 14 or T ≥ 28
T < 4 or T ≥ 24
T ≥ 0